Pump.



No. 703,648. Patented July I, I902. W. F. GARRISON.

P U M P.

(Application filed Feb. 28, 1901.)

(No Model.)

Wrzeawem UNITED STATES PATENT OFFICE.

WILLIAM F. GARRISON, OF BROOKLYN, NEW V YORK, ASSIGNOR TO GUILD &GARRISON, OF BROOKLYN, NEW YORK, 'A FIRM.

PUMP.

SPECIFICATION forming part of Letters Patent No. 703,648, dated July 1,1902.

Application filed February 28, 1901. Serial 110.749.201. (No model.)

To all whom, it may concern:

Be it known that 1, WILLIAM F. GARRISON, a citizen of the United States,and aresident of the borough of Brooklyn, in the city and State ofNewYork, have invented a new and useful Improvement in Pumps, of whichthe following is a specification.

This invention relates to pumps which may be used for various purposes,but which are especially applicable to the compression ofv gases oraeriform fluids to-very high tension.

The object of the improvement is to provide for the return tothepump-cylinder of any leakage which may pass the piston-rod and toprovide for such return in such manner'that the said leakage may eitherbe pre-- vented from mixing with the fresh incoming gas or may bepermitted to mix therewith as may be desirable, as will be hereinafterexplained; and to these ends the invention consists in the novel systemof passages and valves for controlling the same which is hereinafterdescribed and claimed.

The accompanying drawings represent a pump embodying my invention.

Figure 1 is a plan view; Fig. 2, a longitudinal vertical section on theline 2 2 of Fig. 1 ;I Fig. '3, a horizontal section on the line 3 3 ofFig. 2; Fig. 4, a transverse vertical section on the line'4 4. of Fig.1; Fig. 5, a transverse vertical section on the line 5 5 of Fig. 1; Fig.6, a longitudinal vertical section on the line (36ofFig.1.

ais the cylinder, which is open at'both ends and partly surrounded by acasing in which are three chambers 19 c d. The lower chainber b is thesuction-chamber, with which the suction-pipe connects at 7 or S. chamber0 is the discharge-chamber, the outlet of which is at 9 to apassag'ejlO, with which the discharge-pipe is connected at 11. Theintermediate chamber (1, which is in direct and free communication withthe rear or lefthand end of the cylinder a, as shown in Fig. 2, alsocommunicates with the suction-chamber 12 through the inlet-valve e andwith the outlet-chamber cthrough the discharge-valve f. Theoutlet-chamber c is also in uninterrupted communication with the frontend of the cylinder through the opening 9 and passage 10.

The upper.

g is the piston, the rod h of which passes through the last-mentionedend of the cylinder. As thus far described,the several parts may beconsidered as common.

I will now proceed to describe the parts which in combination with theparts described constitute my invention.

From that end of the cylinder-casing at which the cylinder acommunicates with the outlet-chamber 0 there projects in line with thecylinder at a truly-bored cylindrical extensionj,within which works apacked piston.

'5, formed on the rod h. This rod, reduced in size beyond the piston 1',projects beyond the cylinder extensionj and into and through a'prolongation k: of said extension j, beyond which it is to be connectedwith any suitable motor. The part of the rod which works within thecylinderv extension j is furnished with a packingl, which works tightlywithin the bore of the extension lathe said prolongation kand packing Zbeingthe equivalent of a stuffingbox for the rod. From the outer end ofthe extensionjof the cylinder communication is provided for. with theintermediate chamber d and the rear end of the cylinder a through apassage on, which extends along one side of the cylinder, and aself-acting discharge-valve n, which opens outward from said passage tosaid chamber (1. From the end of the passage m below the valve '11,there is a branch 0, leading to the suction-chamber b and fitted with astop-cock or hand-valve p, by which to open and close communication atwill between the suction-chamber'and the outer end of the cylinderextensionj beyond the piston 11.

Suppose the'pump to be in operation. During the forward stroke of thepiston g-that is to say, in the direction of the arrows shown in Figs. 2and 3t-he cylinder at takes in at its rear or left-hand end, through thesuctionvalve 6, a Volume oE'fiu-id equal to the full displacement of thepiston. During its return stroke the piston displaces this volumethrough the discharge-valve f, a proportion of said volume passingthrough the opening 9 and passage 10 and following the piston 9 into thecylinder, at the front or right-hand end thereof, and the remainderbeing discharged at ll. The proportion thus passing depends on thedifference of area between the faces of the piston, the area of one faceincluding only the annular surface which surrounds the rod h and thearea of the other face being equal to the area of the bore of thecylinder. During the next forward stroke of the pistomwhile the cylinderis again filled behind it through the suction-valve e, thedischarge-valve f being closed, the piston forces out through the frontend of the cylinder and through the passages 10 11 that proportion ofthe volume received at the rear end which was not forced out in the lastrearward stroke. It will thus be seen that the pump only takes in thegas during the forward stroke, but discharges during both the forwardand return stroke of the piston. In running under a moderate pressurethe cock or hand-valve 1) may be kept open, as shown in Figs. 4 and 6,and the passage on from the front end of the cylinder extension willthen be open uninterruptedly to the suction-chamber 12 outside of andindependently of its inlet-valves, and whatever leakage passes thepiston i will escape into that chamber and the valve it remain closedand inoperative; but in running under a high pressure the cook 1) shouldbe closed to shut off communication between said passage m and thesuction-chamber b, and then any leakage which may occur around thepiston 2' will be forced out by said piston during its forward strokethrough said passage on and by the opening of the valve 71 will becaused to pass into the intermediate chamber d, wherein it will beretained by the said valve n and the suction-valve e during, the returnstroke of the piston, and whence during the next forward stroke of thepiston it will pass in t0 the cylinder along with the fresh gas takeninto the latter. In this way the leakage is prevented from mixing withthe incoming gas, which is of great importance in the compression ofhighly-volatile gases to a high degree, for the leakage, being gas whichby its compression has been highly heated, if allowed to mix with thefresh incoming gas would so considerably heat and produce the expansionof the latter as to seriously impair the operation of the pump.

roams \Vhat I claim as my invention is- 1. In a pump, the combination ofa cylinder and a piston and piston-rod working therein, a cylindricalextension at one end of the cylinder, a second piston on said rodworking in said extension, a packing for said pistonrod beyond saidsecond piston, a suctionchamber and adischarge-chamber and asuction-valve and a discharge-valve at the other end of the cylinder, anintermediate chamber in free communication with said other end of thecylinder between the suction and discharge chambers and valves, aleakagepassage leading from the space within said cylindrical extensionbetween said second piston and said packing to said intermediatechamber, and a self-opening and self-closing discharge-valve betweensaid passage and said intermediate chamber, substantially as hereindescribed.

2. In a pump, the combination of a cylinder and a piston and piston-rodworking therein, a cylindrical extension at one end of the cylinder, asecond piston on said rod working in said extension, a packing for saidpistonrod beyond said second piston, a suctionchamber andadischarge-chamber and a suction-valve and a discharge-valve at theother end of the cylinder, an intermediate chamber in free communicationwith said other end of the cylinderbetween the suction and dischargechambers and valves, a leakagepassage leading from the space within saidcylindrical extension between, said second piston and said packing tosaid intermediate chamber and having a branch leading to thesuction-chamber, a self-opening and self-closing valve between saidpassage and said intermediate chamber, and a hand-controlled stop-valvein said branch, substantially as herein described.

In testimony that I claim the foregoing as my invention I have signed myname, in presence of two Witnesses, this 27th day of February, 1901.

WILLIAM F. GARRISON.

\Vitnesses:

FREDK. HAYNES, HENRY THIEME.

